happened to me on a short drive today. Did some reading on it, and it seems to usually be related to electronics. Is it ever related to a broken cat? Reason I ask, is, I’d swear when I warm- started the car again (stopped mid trip to pick up my kid) before the light came on, the exhaust note sounded different. Bass-ier, more of a grumble. Possibly lower idle speed. And an occasional random hiss sound. I didn’t notice a glowing cat, but it is a sunny day, so maybe hard to tell? Not sure if it’s related, but earlier the same day, I did disconnect the battery to do some work. And I have had an unknown CEL light recently, my OBD2 scanner just came from amazon on the weekend. I did buy some new coils over the winter, but have not had time to install, guess it’s moved up the priority list.
Hmmmm....not much info to go on but here are my thoughts: 1. The difference in sound was most likely due to the engine going into limp mode, a Slowdown light will shut down one bank. I am leaning toward a faulty catalyst ECU, because the potting compound use by Ferrari is actually fossilized cat feces. This WILL throw a code, so do a scan,making sure that your OBD reader is capable of scanning both banks' ECU's. IF you are throwing a code in one bank, you can swap ECU's and see if the code swaps banks also. 2. An actual cat overheating issue could definitely be related to faulty coils, a known problem on our cars. Your excuse is not realistic. There is always time to change the coils, as it is a 25 minute job, which takes into account the intoxication that is usually apparent while working on cars. Deduct 5-7 minutes for a sober maintenance session, although that is also unrealistic. It probably took longer to write your post than it will to swap your coils. 3. Get an infared thermometer so you can actually measure whether there is a difference in cat temp between both cats. When my car was entering limp mode, one cat was beyond the limits of the thermo, while the offending ECU measured around 200 degrees. 4. An actual cat issue would be last resort for a slow down light, but is possible if it is clogged. New aftermarket cats can be found for under 2 grand, but again, that's the last resort IMO. Do everything else before going this route.
1) I think you might be right. when I let the car cool completely and started it up to put in the garage for the night, it sounded normal again. a scan of the codes produced a lot of them, but I have a sense they might be related: P0300, P0308, P0306, P0305, P0307, P1198. So lots of misfires. still think its the ECU, or maybe a fuel pump? 2)lol...I know it sounds lazy, but my excuse was pretty realistic. This spring, Ive done rotors and pads on all 4 wheels, full brake fluid flush, cf dipped console, new CF steering wheel, new Alpine stereo, and full wash including engine bay. On my Audi I did coils and a new wiper arm (don't ask). My wife and kid have had me shopping for a new waverunner (they were mad that I sold the old one) which I bought last week, as well as getting quotes for an inground pool to be installed. Then, theres the usual management of stock investments, and a career change which has me looking for another job (in god knows what this time). BTW, congrats on having arms like an orangutan that allows you to do coil changes so quickly...my stubby arms make every job in this engine bay take 90 min minimum. they put the engine too far forward and too low down. But theyre done now, will see if they make an impact next time I go for a short drive. On that note, out of curiosity, which way do sockets and extensions roll in the bellypan when dropped in the engine bay, towards the front of the car? Asking for a friend 3) ya I have an ir thermometer...wasn't in the car with me when this all happened though. next time will be better prepared. 4) cats? who needs cats? they just did away with bi-annual emissions inspections here. 5) thanks for the detailed response!
Yikes, that's a lot of misfire codes, in this case it could well be the cat ecu is doing it's job. The cat temp ECU's are very failure prone, but your codes tell me the engine needs to be checked out possibly the O2 sensor is causing it to run too rich. Incidentally, I've chased slow down lights on 355's and 360's for a while now and now have a very good understanding of their operation. I have been working on a replacement more reliable cat temp ecu and it is very near to production. A few guys in the 355 forum are helping me test, but I have just run my first prototypes in my 360 over the last week with perfect results. Once I have these in production I will spread the word. https://www.ferrarichat.com/forum/threads/replacement-slow-down-cat-ecu-prototype.600772/ You've done the right thing by not ignoring a slow down light. Hopefully your fix is straightforward.
Last summer after a very long trip (to Quebec City) the SDL came on. I had bought a spare Cat ECU that I carried around and so I picked the left side and swapped it (20 min job). Haven't seen it appear yet (appeared I luckily picked the correct side).
I've just added feature to Swiss Army Knife to delete the Slow Down feature and as I was analyzing it I got thinking. I may be able to use the temperature from the Wideband primary o2 sensor to avoid use of thermocouplers altogether and just modify the code to look at those temps instead. Not sure yet if they can read high enough though until I look at the data sheet. Failing that I also found the linearization lookup tables inside the code. The way this looks to me (Without digging deeper) is that the Voltage coming back from the thermocoupler is probably not compatible with direct connection to the engine ecu's (voltages too high), hence Ferrari's solution to use the cat ecu converters which are actually quite simple (and should be very cheap!). Typically on these older ecus they expected sensors to output an analgoue voltage between 0-5V so all that cat ecu is actually doing is the work of voltage translation into a format that the ecu can accept. When i get some time I will source an inexpensive replacement for both the pair of thermocouplers and cat ecu's. After all, all these are doing is converting the non-linear high voltages coming back from the thermo's and converting them (A to D) into millivolts signal at the 0-5V linear (e.g. 4mV/°C) output so it's compatible with ecu's built in conversion tables. Since I've now isolated the exact functions in the code I can make these plug in and play. I think they could be sourced at a tiny fraction of the price of the Ferrari items, thinking full set of 2 thermocouplers and a ecu conversion could be less than $100 all in and it would be plug in and play.. I'll come back on this subject when I get a bit more time.
It is an amplified variable resistor. There is no ADC in it, only an analog signal 0-5V comes out to the main ECU.
Yes the a2d is in the engine ecu.. I can see the code that does it. So not really an ecu in my book. More a converter to work around limitations of original thermocouples used and engine ecus voltage ranges for sampling.
I’ve encountered it randomly as well during normal driving. This will probably sound silly, but after I changed to a new batt and a new clutch,it’s never come back on again so far. I’m no expert on the electronics , so I’ve no clue how this could correlate. NB: God forbid it’s the clutch giving u issues though, that’s pricey to change. [emoji23] “Sharing is Caring...”
It's based on fairly industry standard instrumentation amplifier circuit for K-type thermocouples - I can confirm it's a 100% analogue electronic design. My circuit is complete and 100% replicating the factory vescovini behaviour, hopefully with much increased reliability. There are some differences between off the shelf thermocouple amps, namely a 0.5v output/offset up to about 200 degrees C, and a maximum output of 4.5v at the top end which have all been documented before on this site. Output is a simple 5mv/degree C based on thermocouple voltage input. There is a fair amount of signal conditioning and filtering required as thermocouple signals are just a few millivolts, and this needs to be measured in an environment full of spark plugs and electrical noise. Good common mode noise rejection is critical. Also there needs to be some detection of open circuit thermocouples to give 100% confidence in the system working (this is where the factory boxes fall over). My circuits will be MUCH less cost than the factory option which my perhaps slightly cynical view is they are treating as a high margin revenue stream. Why should they increase reliability when their bottom line would take a hit.... I shall soon fix that and make these things available to everyone. The concept is sound and important to have working properly in these performance cars, just the parts Ferrari put in there were not the greatest quality. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Excellent. Well done indeed. Where can one order these replacements from and how much? Pm me if you prefer.
I will setup a pretty simple website to get these things available to the community. I just want to confirm reliability first before I commit any promises to anyone. I have a test unit going to Dr Bob of 355 forum fame as he has a full data logging setup in his vehicle. I currently have one of each Vescovini / my design in my 360 and am testing on that platform. I also want to get it into an EMC chamber to test noise immunity once first shakedown reliability is complete (because that testing is $$$$). Once done I will be good to go and should be able to churn out quite a few dozen at a time. About 6-7 weeks I estimate to have first units ready.
I hear you loud and clear. I'm doing a Ferrari Swiss Army Knife tool and going through all of the same for that too.. [emoji12]
I hope youre right. I changed the coils, reset the ecu and put the battery on the smart charger. Took it for a drive, about the same duration/distance as when this stuff happened. Nothing happened. No CEL, or Slow Down. Checked exhaust temps when I got home, both were about equal and not excessive (highest temp recorded was about 250 deg Cel.). funny you mention battery though, it did seem to need longer than usual to be topped up by the smart charger, and It seemed like it was harder to turn over to start. Is it really possible to get this much nonsense from a battery on its way out? I sure hope that's all it is, I did some reading on others with full bank misfires and it seems to point to a bad ecu, which sounds like a big ordeal to get/swap, esp since their made differently for manual cars like mine vs F1. It could end my summer of driving.
They are fairly sensitive to voltage. There are a few places the wiring harness can wear through as well causing random issues but mostly works. The CAN bus is a differential bus so wearing through the insulation on one wire and grounding it intermittently causes noise on the bus but won't short out the signals so it will mostly work.
Depends on whether you have extra aftermarket electronics. I suggested this in another thread as well. Camera and sound system amp if not done correctly can really screw the electronics up royally. Strikes me that something may be draining ur battery more than it should. My amateur opinion is that it’s not a bad ECU, otherwise you’d have more problems than this. If you have no aftermarket installed electronics , I would be kinda surprised though . This might sound silly again , but maybe u wanna check your power window buttons. They are supposed to turn on when u open the door , and after 3-5 mins after u lock the doors, they should go off. When this gets spoilt , they don’t turn off, and remain on permanently, this could cause extra drain on ur battery. Some sound/cam shops do shortcuts and tap the easy outputs , example the cig lighter. It’s easier on them cuz they don’t have to sort out the gazillion wires tied together . And the issue with this is , it could bypass your cam cutoff voltage , meaning the cam is draining non stop. Just suggesting heh, from my experience on other cars. (PS. For ur sake , I hope it ain’t the clutch either heh[emoji847]) “Sharing is Caring...”
Funny you should mention the power windows / door lock module, it's another one just like the immobilizer ecu which has dreaded soldered on relays on the pcb. What a joke, really no excuse not to put them in the front compartment along with all the other relays.. .. They are used to drive the lock and window states and as you have discovered they can also drain battery like nobody's business in exactly same manner as a (extremely common) immobilizer failure when the relays go bad.
Worst part of this is, it stealthily drains. As Long as the windows don’t stop working altogether , I don’t think anyone waits around to see if the lights go off or not. “Sharing is Caring...”
Ok, this is interesting. Right before the slow down incident, I had a new Alpine head unit installed (no amp, but it has an iPad sized screen) and a reverse cam. I had a CEL light on, prior to that, but I suppose it could have been anything...bad coil maybe? I went for another drive, slightly longer than the last, and longer than the one I got the slow down message on, and it was uneventful, and exhaust and cat temps were not high upon return...250 deg cel at most, I think, measured at various points. So I think I’m going to focus on the battery for now. It’s an interstate, 3+ years old, kept charged, but I don’t know much about it. I’ll put it on my old analog load tester and see what it says. If my hunch is correct, I’ll be ordering an Odyssey 48-720 agm battery next week. Thanks!
